Rolling mill



Jan. 31, 1933. CQE 1,895,607

ROLLING MILL Filed March 22, 1930 I Patented Jan. 31, 1933 UNITED STATES .PATENTi OFFICE JAMES R. COE, OF WATERBURY, CONNECTICUT, ASSIGNOR TO THE AMERICAN BRASS COMPANY, OF WATERBURY, CONNECTICUT, A CORPORATION OF CONNECTICUT ROLLING MILL Application filed March 22, 1930. Serial No. 438,136.

This invention relates to rolling mills for rolling fiat strip or sheet metal, and part cularly to the cluster type of rolling mill in which there are one or more work rolls of comparatively small diameter each supported by a backing roll of considerably greater diameter and strength, and it is an object of the invention to so construct the backing roll or rolls as to secure sufficient contact between the backing roll and the working roll to prevent crushing or distorting of the surfaces of the rolls, or cause excessive springing or bending of the work. roll.

Referring to the accompanying drawing the figure is a front elevation of a four-high rolling millshowing my improved construction, the shape of the rolls being considerably exaggerated for clearness of illustration.

' In the drawing, in illustrating the principle of my invention, I have shown merely in outline the rolls of a so called four-high mill comprising two Working rolls 10 of comparatively small diameter, and a backing roll 11 for each work roll of considerably greater diameter and strength. It will, of course, be understood that the necks 14 and 15 of these rolls each run in suitable bearings in the usual housings which are not shown in the drawing to simplify the illustration, and that these hearings and housings are supplied with the usual means for relatively adjusting the work rolls for different gauges ofmetal. Also that the usual driving means is provided for the work rolls.

It has been found from actual experience from the use of this type of rolling mill that it is difficult or practically impossible to eliminate a certain deflection of the work roll under the pressure of rolling the metal strips or sheets and, therefore, with so-called flat or cylindrical rolls of uniformdiameter throughout, the metal strip is not rolled flat, but is thicker in the center than at the edges due to the deflection of the roll. Therefore, to overcome this difficulty, the working roll is crowned somewhat to compensate for this deflection. That is, its surface is convexed somewhat longitudinally as indicated at 12 in the drawing so that the roll is of somewhat larger diameter at the center than at the ends. This curvature is shown greatly exaggerated in the drawing so that it will show up more clearly. With this shape of roll, the curvature compensates for the deflection caused by the pressure on the metal strip being rolled and fiat strips or sheets, or that is, strips or sheets of uniform thickness, can be produced with these rolls.

However, when this crowned working roll is operated in connection with a flat backing roll or that is, a backing roll of uniform diameterthroughout, it will be evident that the contact between the rolls is practically a point and the entire pressure of operation must be taken by this limited surface of contact. This pressure in operation is suflicient to crush or distort the surfaces of the backing roll and work roll permitting excessive springing and bending of the work roll so as not to give a satisfactory finish to the metal being rolled. I have overcome this objection by concaving or forming the surface of the backing roll longitudinally as indicated at 13 to fit the surface of the work roll. That-is, making this roll of somewhat smaller diameter at its center than at its ends. It will be apparent that the contact between the small work roll and the backing roll will thus be substantially a line extending throughout the entire length of the rolls and, therefore, the pressure and wear between the rolls instead of being at a point as where fiat backing rolls are used, will be distributed throughout the length of the rolls and distorting, crush ing and injuring of the surfaces are prevented.

Having thus set forth the nature of my invention, what I claim is:

1. In a rolling mill, a small workin roll 'convexed longitudinally so that it is of greater diameter at its center than at its ends, and a larger backing roll for the work roll engaging the surface thereof and on which the working roll rolls, the surface of the backing roll being concaved longitudinally so that it is of less diameter at its center than at its ends and substantially corresponds to the curvature of the working roll to support it throughout its length.

2. In a rolling mill, a relatively small workin roll having its surface convex longitudinal y so that it is of lar er diameter at its midlength than at its en s, and a larger backing roll for the working roll having its surface concave longitudinally so that it is of less diameter at its midlength than at its ends and substantially corresponds to the curvature of the working roll to support it throughout its length.

3. In a rolling mill, a working roll having its surface convex longitudinally so that as it yields under rolling strain it will roll a flat strip, and a. backing roll for the work roll having its surface concave longitudinally to substantially correspond with the surface of the work roll to support it throughout its length. I

4. In a rolling mill, a pair of opposed working rolls of relatively small diameter having their surfaces-convex longitudinally of the rolls so that they are of larger diameter at their centers than at their ends, and a backing roll for each work roll having its surface concave longitudinally to substantially correspond with the curvature of the adjacent Work roll to support it throughout its length anals is of less diameter at its center than at its en In testimony whereof I aflix my signature.

JAMES R. COE. 

